Pairs Sentence Examples

Multiple pairs of feet hurried down the hall and Connie was the first one through the door.

The maximum number of teeth is 36, there being typically two pairs of incisors and three of premolars in each jaw.

The tail is long and in some cases prehensile; the first hind-toe may be either large, small or absent; the dentition usually includes three pairs of upper and one of lower incisors, and six or seven pairs of cheekteeth in each jaw; the stomach is either simple or sadculated, without a cardiac gland; and there are four teats.

With the exception of the aberrant long-snouted phalanger, the members of the family Phalangeridae have the normal number of functional incisors, in addition to which there may be one or two rudimentary pairs in the lower jaw.

Here he seeks a female, pairs, and soon afterwards dies.

The conductors are then twisted in pairs with definite lays.

The gonads are borne on the manubrium, either forming a continuous ring (Codonid type), or four masses or pairs of masses (Oceanid type).

The tail is rudimentary, the first hind-toe opposable, the first pair of upper incisors very large, but the second and third either absent or small and placed partially behind the larger pair; and only five pairs of cheek-teeth in each jaw.

They consist of two rows of balls rolling in two pairs of V races or grooves.

In male beetles, however, the two pairs of genital processes (paramera) belonging to the ninth abdominal segment are always present, though sometimes reduced.

For example, the grub of a pea or bean beetle (Bruchus) is hatched, from the egg laid by its mother on the carpel of a leguminous flower, with three pairs of legs and spiny processes on the prothorax.

The larvae have the three pairs of legs well developed, and the hinder abdominal segments swollen.

Riley, who finds that the young larva, hatched from the egg laid on the pod, has three pairs of legs, and that these are lost after the moult that occurs when the grub has bored its way into the seed.

Every axle of an electric locomotive may thus be subjected to a torque, and the large weight which must be put on one pair of wheels in order to secure sufficient adhesion when all the driving is done from one axle may be distributed through as many pairs of wheels as desired.

The prevalent number of testes is one pair in the aquatic genera and two pairs in earthworms. But there are exceptions; thus a species of Lamprodrilus has four pairs of testes.

Associated with these glands are frequently to be found bundles or pairs of long and variously modified setae which are termed penial setae,to distinguish them from other setae sometimes but not always associated with rather similarglandswhich are found anteriorly to these, and often in the immediate neighbourhood of the spermathecae; the latter are spoken of as genital setae.

In many Geoscolicidae, however, and certain Lumbricidae and Perichaetidae, there are several, even a large number, of pairs of very small spermathecae to each of the segments which contain them.

The intestine has a pair of caeca or two or three pairs (but all lie in one segment) in the genus Pheretima and in one species of Rhinodrilus.

There are three pairs of spermathecae situated in segments III-V, a testis in V and an ovary in VI.

The nervous system is embedded in the epidermis, and the pairs of ganglia are separated as in Serpula, &c.; each pair has a longish commissure between its two ganglia.

There are no setae and apparently only two pairs of nephridia, of which the anterior pair open commonly by a common pore on the third segment after the head, whose segments have not been accurately enumerated.

The male ducts are either one pair or two pairs, which open by a common and complicated efferent terminal apparatus furnished with a protrusible penis.

The three pairs of pigmented spots show the position of the eyes on the dorsal surface.

The testes vary in numbers of pairs.

In both 1715 and 1745 Dumfries remained apathetic. Prince Charles Edward indeed occupied the town, holding his court in a building afterwards known as the Commercial Hotel, levying £2000 tribute money and requisitioning 1000 pairs of shoes for his Highlanders, by way of punishing its contumacy.

Two pairs of salivary ducts, each leading from a salivary gland, open into the buccal chamber.

The head in most cases bears two pairs of tentacles.

It carries two pairs of cephalic tentacles and a pair of sessile eyes.

Head bears two pairs of tentacles.

Body furnished with three pairs of lateral lobes, bearing the tegumentary papillae; foot very narrow; pelagic. Glaucus.

Pulmonata with two pairs of tentacles, except Janellidae and Vertigo; these tentacles are invaginable, and the eyes are borne on the summits of the posterior pair.

The head of an insect carries usually four pairs of conspicuous appendages - feelers, mandibles and two pairs of maxillae, so that the presence of four primitive somites is immediately evident.

From these three pairs of thoracic legs comes the name - Hexapoda - which distinguishes the class.

Two pairs of wings are present in the vast majority of insects, borne respectively on the mesothorax and metathorax.

The legs, wings and other organs of the trunk receive their nerves from the thoracic and abdominal ganglia, and the fusion of several pairs of these ganglia may be regarded as corresponding to a centralization of individuality.

They are developed on the ventral surface of the body and are six in number, one pair arising from the eighth ventral plate and two pairs from the ninth.

The ganglia become greatly changed in position during the later life, and it is usually said that there are only ten pairs of abdominal ganglia even in the embryo.

In Orthoptera, Heymons has demonstrated the existence of eleven pairs, the terminal pair becoming, however, soon united with the tenth.

First maxillae also modified as piercers; maxillae of both pairs with distinct palps.

Both pairs of wings similar, narrow and fringed.

Of special interest are cockroachlike forms, with two pairs of similar membranous wings and a long ovipositor, and gigantic insects allied to the Odonata, that measured 2 ft.

The Corrodentia retain vestigial maxillulae and two pairs of Malpighian tubes, but the wings are somewhat specialized in the Copeognatha and absent in the degraded and parasitic Mallophaga.

It included all Picariae which had not " zygodactylous " feet, that is to say, toes placed in pairs, two before and two behind.

Two pairs of invaginations of B the skin, which originally are called the prostomial and metastomial disks, grow round the intestine, finally fuse together, and form the skin and mus- cular body-wall of the future Nemertine, which afterwards becomes ciliated, frees itself from the pilidium investment and develops into the adult worm without further metamorphosis.

Its integument is marked by a large number of transverse grooves simulating the segmentation of Annelids, and near the anterior extremity close to the mouth are two pairs of recurved chitinous hooks.

Again, the adult Pentastomum shows no trace of appendages, unless the two pairs of chitinous hooks are to be regarded as the vestiges of jaws or ambulatory limbs.

These larvae are minute oval creatures with a comparatively short apically fringed caudal prolongation and furnished with two pairs of short two-clawed processes, which may represent the limbs of anthropods and possibly the two pairs of legs found in Acari of the family Eriophyidae.

There are three pairs of cheek-teeth which are rooted, and show folds of enamel on the crown.

According to this theory a " chemical type " embraced compounds containing the same number of equivalents combined in a like manner and exhibiting similar properties; thus acetic and trichloracetic acids, aldehyde and chloral, marsh gas and chloroform are pairs of compounds referable to the same type.

A doubly linked pair of atoms is denoted by the sign A with the index corresponding to the side; if there are two pairs of double links, then indices corresponding to both sides are employed.

These bands are due to molecular oscillations; Hartley suggests the carbon atoms to be rotating and forming alternately single and double linkages, the formation of three double links giving three bands, and of three single links another three; Baly and Collie, on the other hand, suggest the making and breaking of links between adjacent atoms, pointing out that there are seven combinations of one, two and three pairs of carbon atoms in the benzene molecule.

For example, episomorphs of white potash alum and violet chrome alum, of white magnesium sulphate and green nickel sulphate, and of many other pairs of salts, have been obtained.

Each opens in a vas deferens which bears three diverticula or vesiculae seminales, and three pairs of cement glands also are found which pour their secretions through a duct into the vasa deferentia.

There are but three pairs of incisor teeth in each jaw, and the upper molars are tricuspid.

A large number of representatives of the group are known from both the Old and the New World; specialization displaying itself in the later ones in the development of dermal horns over the nasal bones, either in laterally placed pairs as in some of the early forms, or in the median line, either single or double.

This cipher alphabet is called Albam, from the first interchangeable pairs.

Thus the rational number one, which we will denote by ' r, is not the cardinal number I; for t r is the relation I/I as defined above, and is thus a relation holding between certain pairs of cardinals.

The main armament of the battleships was to be three pairs of 12-in.

The armoured cruiser was to carry four pairs of 9.2-in.

The dorsal skeletal elements of the thorax and of the anterior six abdominal segments unite with the wing-cases to form a large respiratory chamber, containing five pairs of tracheal gills, with lateral slits for the inflow and a posterior orifice for the outflow of water.

In 1865 Kowalevsky discovered that the organs of respiration consist of numerous pairs of gill-slits leading from the digestive canal through the thickness of the body-wall to the exterior.

The flowers are regular, with four free sepals arranged in two pairs at right angles, four petals arranged crosswise in one series, and two sets of stamens, an outer with two members and an inner with four, in two pairs placed in the middle line of the flower and at right angles to the outer series.

In Rhynchonella, where there are two pairs of kidneys, the internal opening of the anterior pair is supported by the gastroparietal band and that of the posterior pair by the ileoparietal band.

Two other pairs have been termed divaricators by Hancock, or cardinal muscles (" muscles diducteurs " of Gratiolet), and have for function the opening of the valves.

Two pairs of muscles, apparently connected with the peduncle and its limited movements, have been minutely described by Hancock as having one of their extremities attached to this organ.

The cirri or tentacles, of which three or four pairs are present, are capable of being protruded, and the minute larva swims by means of the ciliary action they produce.

Moreover, instead of having one pair of variables x i, x2 we may have several pairs yl, y2; z i, z2;...

A particular quantic of the system may be of the same or different degrees in the pairs of variables which it involves, and these degrees may vary from quantic to quantic of the system.

The quartic will have two pairs of equal roots, that is, will be a perfect square, if it and its Hessian merely differ by a numerical factor.

The flowers, which are solitary, or rarely in pairs, at the end of slender axillary flower-stalks, are very irregular in form, with five sepals prolonged at the base, and five petals, the lowest one larger than the others and with a spur, in which collects the honey secreted by the spurs of the two adjoining stamens.

The second is Fechner's method; it consists of recording the changes in feeling-tone produced in a subject by bringing him in contact with a series of conditions, objects or stimuli graduated according to a scientific plan and presented singly in pairs or in groups.

Denoting the two pairs of magnetic poles by N, S and N', S', there is attraction between N and S', and between S and N'; repulsion between N and N', and between S and S'.

This region corresponds in both cases to six somites, as indicated by the presence of six pairs of limbs.

The next four pairs of appendages (completing the mesosomatic series of six) consist, in both Scorpio and Limulus, of a base carrying each 130 to 150 blood-holding, leaf-like plates, lying on one another like the leaves of a book.

Both belong to the category of " coelomoducts," namely, r- ' tubular or funnel-like portions of the coelom opening to the exterior in pairs in each somite (potentially,) and usually persisting in only a few somites as either "urocoels" (renal organs) or "gonocoels"(genital tubes).

In Limulus small entosternites are found in each somite of the appendage-bearing mesosoma, and we find in Scorpio, in the only somite of the mesosoma which has a welldeveloped pair of appendages, that of the pectens, a small entosternite with ten pairs of muscles inserted into it.

The coxae of the five pairs of limbs following the chelicerae were arranged in a series on each side between the mouth, M, and the metasternites, mets.

Opening in pairs in each somite, right and left into the pericardial sinus are large veins, which bring the blood respectively from the gill-books and the lungbooks to that chamber, whence it passes by the ostia into the heart.

Limulus has two pairs of these, Scorpio as many as six pairs.

Four pairs of appendages besides these are seen to belong to the cephalic tergum.

The alimentary canal is uncoiled and cylindrical, and gives rise laterally to large gastric glands, which are more than a single pair in number (two to six pairs), and may assume the form of simple caeca.

Mesosomatic segments furnished with large plate-like appendages, the 1st pair acting as the genital operculum, the remaining pairs being provided with branchial lamellae fitted for breathing oxygen dissolved in water.

The appendages of the mesosoma generally suppressed; in the more primitive forms one or two pairs may be retained as organs subservient to reproduction or silkspinning.

Mouth situated more forwards than in Delobranchia, no share in mastication being taken by the basal segments of the 5th and 6th pairs of prosomatic appendages.

Appendages of 1st pair.tri-segmented, chelate; of 2nd pair chelate, with their basal segments subserving mastication; of 3rd, 4th, 5th and 6th pairs similar in form and function, except that in recent and Carboniferous forms the basal segments of the 3rd and 4th are provided with sterno-coxal (maxillary) lobes, those of the 4th pair meeting in the middle line and underlying the mouth.

Remaining pairs of appendages similar in form and function, each tipped with two or three claws.

The posterior pulmonary sacs (except in Hypochilus) replaced by tracheal tubes; the anterior and posterior pairs replaced by tracheal tubes in the Caponiidae.

Remaining pairs of appendages with their basal segments immovably fixed to the sternal surface, similar in form, the posterior three pairs furnished with two claws supported on long stalks; the basal segments of the 6th pair bearing five pairs of tactile sensory organs or malleoli.

The segmentation of the prosoma and the form of the appendages bear a homoplastic similarity to the head, pro-, meso-, and meta-thorax of a Hexapod with mandibles, maxillary palps and three pairs of walking legs; while the opistho io i e d c b o a S' S" 2 I VT V S IV III II I Opisthosoma Prosoma FIG.

Appendages of the 3rd, 4th, 5th and 6th pairs similar in form and function, tipped with two claws, their basal segments in contact in the median ventral line.

Appendages of 3rd, 4th, 5th and 6th pairs similar in form; their basal segments in contact in the middle line and immovably welded, except those of the 3rd pair, which have been pushed aside so that the bases of the 2nd and 4th pairs are in contact with each other.

I to VI, The six pairs of appendages of the prosoma, the last three cut short.

In the Phalangiotarbi the appendages resembled those of the Anthracomarti, except that the basal segments of the last four pairs were usually approximated in the middle line leaving a long and narrow sternal area between; and the carapace of the prosoma was unsegmented.

Tracheae typically opening by stigmata situated in the articular sockets (acetabula) of the 3rd, 4th, 5th and 6th pairs of appendages.

Then again, the ears are large in proportion to the head, the pupil of the eye is elliptical and vertical when in a strong light, and the female has six pairs of teats, in place of the three to five pairs found in dogs, wolves and jackals.

With the exception of certain South African species, foxes differ from wolves and jackals in that they do not associate in packs, but go about in pairs or are solitary.

It is stated to live usually in pairs, and to eat rats, birds, frogs, white ants and various insects, and in the north of India it is accused of digging out dead bodies, and several of the native names mean "grave-digger."

The problem of finding the sum of r terms is aided by graphic representation, which shows that the terms may be taken in pairs, working from the outside to the middle; the two cases of an odd number of terms and an even number of terms may be treated separately at first, and then combined by the ordinary method, viz.

Within the rectangle formed by pairs of consecutive dark lines, and not far from its centre, the brightness rises to a maximum; but these subsequent maxima are in all cases much inferior to the brightness at the centre of the entire pattern (=o, n =o).

Obelisks were usually raised on pedestals of cubical form resting on one or two steps, and were set up in pairs in front of the entrance of temples.

Unlike the other members of the group, the avahi is nocturnal, and does not associate in small troops, but is met with either alone or in pairs.

As in the other typical South American edentates, there are no teeth in the front of the jaws, while those of the cheek-series usually comprise five pairs in the upper and four in the lower.

It has large compound leaves composed of four or five pairs, with a terminal odd one, of short-stalked, oblong, blunt, leathery leaflets, and inconspicuous green flowers.

The grouping of the forms 5 to Io with II to 16 is designed to show that the pairs 5, II for example become identical when the terminal groups are the same.

The small flowers or spikelets are borne in pairs on the ultimate branches of a much branched feathery plume-like terminal grey inflorescence, 2 ft.

The four suckers are here united to form two pairs or fused into a single pair.

Although occasionally seen in large flocks, the mara is more commonly found in small parties or in pairs, the parties commonly moving in single file.

The blackbird is of a shy and restless disposition, courting concealment, and rarely seen in flocks, or otherwise than singly or in pairs, and taking flight when startled with a sharp shrill cry.

A more efficient arrangement consists of a stack of vertical pipes standing up from a main or collecting trough and connected at the top in consecutive pairs by a cross tube.

These pairs of observations have shown a parallax from which the elevation of the objects above the earth, the lengths and directions of their courses, &c. could be computed.

In the male flowers, which are numerous, the stamens are sixteen in number and arranged in pairs; the female flowers are solitary, with traces of stamens, and a smooth ovary with one ovule in each of the eight cells - the ovary is surmounted by four styles, which are hairy at the base.

Another variety has a red back, with pairs of black crossbars, the bands of each pair being separated by a narrow yellow space; sides brown, dotted with black; belly dark green, the outer portion of each ventral shield being yellow,.

The sheets meet in pairs along three lines which themselves meet in a point.

In general the main elevations of the two ranges form pairs lying opposite one another; the forms of both ranges are monotonous, but the colouring is splendid, especially when viewed from a distance; when seen close at hand only a few valleys with perennial streams offer pictures of landscape beauty, their rich green contrasting pleasantly with the bare brown and yellow mountain sides.

Earlier in the work, however, we have the adventures of Brutus; of his follower Corineus, the vanquisher of the Cornish giant Goemagol (Gogmagog); of Locrinus and his daughter Sabre (immortalized in Milton's Comus); of Bladud the builder of Bath; of Lear and his daughters; of the three pairs of brothers, Ferrex and Porrex, Brennius and Belinus, Elidure and Peridure.

Hence we see that if the whole surface of the sphere is divided into pairs of elements by cones described through any interior point, the resultant force at that point must consist of the sum of pairs of equal and opposite forces, and is therefore zero.

Let V be the potential at the centre of the prism, then the normal forces on the two faces of area dy.dx are respectively RI dx2 d xl and (dx 2 d x), dV d2 and similar expressions for the normal forces to the other pairs of faces dx.dy, dz.dx.

The only sense organs described are eyes, which occur in some species, and may number one to four pairs.

Uintatheres were huge creatures, with long narrow skulls, of which the elongated facial portion carried three pairs of bony horn-cores, probably covered with short horns in life, the hind-pair being much the largest.

Both foreand hindwings are usually present, both pairs being membranous, the hindwings small and not folded when at rest, each provided along the costa with a row of curved hooks which catch on to a fold along the dorsum of the adjacent fore-wing during flight.

The gullet leads into a moderate-sized crop, and several pairs of salivary glands open into the mouth.

The Tenthredinidae, or true saw-flies, are distinguished by two spines on each fore-shin, while the larvae are usually caterpillars, with three pairs of thoracic legs, and from six to eight pairs of abdominal prolegs, the latter not possessing the hooks found on the pro-legs of lepidopterous caterpillars.

Within the groove of the rostrum two pairs of slender piercers - often barbed at the tip - work to and fro.

The typical insectan ovipositor with its three pairs of processes, one pair belonging to the eighth and two pairs to the ninth abdominal segment, can be distinguished in the female.

There is usually a marked difference between the wings of the two pairs.

After several moults the rudiments of two pairs of wings appear, and then the insect creeps up to the surface of the earth, and on to the vine.

The words douze pairs were anglicized in a variety of forms ranging from douzepers to dosepers.

At the beginning of the 13th century there existed a tour des pairs which exercised judicial functions and dated possibly from the 11th century, but their prerogatives at the beginning of the 14th century appear to have been mainly ceremonial and decorative.

This micrometer is provided with two pairs of parallel webs.

The area is laid out by two pairs of level drifts, parallel to each other, about 150 yds.

In laying out the mine it is customary to drive the levels or roads in pairs, communication being made between them at intervals by cutting through the intermediate pillar; the air then passes along one and returns by the other.

The increased resistance, due to the large extension of workings from single pairs of shafts, the ventilating currents having often to travel several miles to the upcast, has led to great increase in the size and power of ventilating fans, and engines from 250 to Soo H.P. are not uncommonly used for such purposes.

For flat ropes the drum or bobbin consists of a solid disk, of the width of the rope fixed upon the shaft, with numerous parallel pairs of arms or horns, arranged radially on both sides, the space between being just sufficient to allow the rope to enter and coil regularly upon the preceding lap. This method has the advantage of equalizing the work of the engine throughout the journey, for when the load is greatest, with the full cage at the bottom and the whole length of rope out, the duty required in the first revolution of the engine is measured by the length of the smallest circumference; while the assistance derived from gravitating action of the descending cage in the same period is equal to the weight of the falling mass through a height corresponding to the length of the largest lap, and so on, the speed being increased as the weight diminishes, and vice versa.

When two bodies are said in ordinary language to be in contact, all that is meant is that they are so near together that the repulsion between the nearest pairs of atoms belonging to the two bodies is very great.

Another genus has been described from the Pleistocene of Nebraska, as Paramylodon; it has only four pairs of teeth, and an elongate skull with an inflated muzzle.

The body is elongated and furnished with four pairs of short, unjointed, stump-like legs, each terminated by a pair of claws.

These last characteristics also separate them essentially from the Pycnogonida, some members of which resemble them to a certain extent in having only four pairs of limbs, no gnathites, no respiratory organs, a ganglionated ventral nervous system, and the abdomen reduced to a mere rudiment projecting between the last pair of legs.

Then we can take the strips in pairs, and treat each pair as a parabolic trapezette.

The calculation of the expressions in brackets may be simplified by taking the pairs in terms from the outside; by finding the successive differences of uo + um, ill + um_l, ..., or of uI u i +umi, ..

An ohmmeter in one form consists of two pairs of coils, one pair called the series coil and the other called the shunt coil.

As many as 700 pairs of golden spurs were collected on the field from the bodies of French knights and hung up as an offering in an abbey church of the town, which has long disappeared.

The pairs of rafts are joined by three baulks 15 ft.

These are generally species of the genus Penaeus (like P. caramote of the Mediterranean) which are distinguished from all those already mentioned by having pincers on the first three, instead of only on the first two pairs of legs.

They bought practically all of what is now Essex county from the Indians for "fifty double hands of powder, one hundred bars of lead, twenty axes, twenty coats, ten guns, twenty pistols, ten kettles, ten swords, four blankets, four barrels of beer, ten pairs of breeches, fifty knives, twenty horses, eighteen hundred and fifty fathoms of wampum, six ankers of liquor (or something equivalent), and three troopers' coats."

The third and fourth books, like the larger part of the second, treat of ethics; the third, of virtues and vices, in pairs; the fourth, of more general ethical and political subjects, frequently citing extracts to illustrate the pros and cons of a question in two successive chapters.

In conformity with these reductions the breastbone of the moas is devoid of any coracoidal facets; there is no trace of a keel, and the number of sternal ribs is reduced to three or even two pairs.

In other varieties of Patience the object is to make pairs, which are then discarded, the game being brought to a successful conclusion when all the cards have been paired; or to pair cards which will together make certain numbers, and then discard as before.

In practical work, the low resistances take the form of certain strips of metal which have on them two pairs of terminals, one termed " current terminals," and the other " potential terminals."

The second antennae, mandibles and two pairs of maxillae may also be claimed as of malacostracan type.

To these succeed eight pairs of foliaceous branchial appendages on the front division of the body, followed on the hind division by four pairs of powerful bifurcate swimming feet and two rudimentary pairs, the number, though not the nature, of these appendages being malacostracan.

In the male the first one or two pairs of feet are modified into grasping organs.

The mandibles are without palp. The pairs of feet are four to six.

The former, with the feet for the most part concealed by the carapace, is subdivided into two tribes, the Ctenopoda, or " comb-feet," in which the six pairs of similar feet, all branchial and nonprehensile, are furnished with setae arranged like the teeth of a comb, and the Anomopoda, or " variety-feet," in which the front feet differ from the rest by being more or less prehensile, without branchial laminae.

The Gymnomera, with a carapace too small to cover the feet, which are all prehensile, are divided also into two tribes, the Onychopoda, in which the four pairs of feet have a toothed maxillary process at the base, and the Haplopoda, in which there are six pairs of feet, without such a process.

The limbs, including antennae and mouth organs, never exceed seven definite pairs.

These have the furcal branches broad, lamellar, with at least three pairs of strong spines or ungues.

The next, the copepodid or cyclopid, stage is characterized by a cylindrical segmented body, with foreand hind-body distinct, and by having at most six cephalic limbs and two pairs of swimming feet.

Giesbrecht and Hansen have shown that the mouth-organs consist of mandibles, first and second maxillae and maxillipeds; and Claus himself relinquished his long-maintained hypothesis that the last two pairs were the separated exopods and endopods of a single pair of appendages.

The majority are distinguished from snakes by the possession of two pairs of limbs, of external ear-openings and movable eyelids, but since in not a few of the burrowing, snake-shaped lizards these characters give way entirely, it is well-nigh impossible to find a diagnosis which should be absolutely sufficient for the distinction between lizards and snakes.

But the limbs show with regard to development great variation, and an uninterrupted transition from the most perfect condition of two pairs with five separate clawed toes to their total disappearance; yet even limbless lizards retain bony vestiges beneath the skin.

The agamas have always two pairs of well-developed limbs.

Typically there are two pairs - a proximal, more or less approximated on the postero-dorsal surface, and a distal pair, more widely separate.

They are six in number, median, ventral and dorsal, and two unequal lateral pairs.

It is, in common with others, a hollow process into which run two pairs of broad, coarsely transversely striated muscles.

There are also two pairs of distal antennae.

The jaguar is usually found singly (sometimes in pairs), and preys upon such quadrupeds as the horse, tapir, capybara, dogs or cattle.

The magistrates were elected annually, and were six in number, forming three pairs of colleagues.

The lower canines are much more slender, but follow the same curve; except on the posterior surface, their crowns are covered with enamel; both pairs of canines are large in the two sexes.

Structurally the Neuroptera are distinguished by elongate feelers, a large, free prothorax, a labium with the inner lobes of the second maxillae fused together to form a median ligula, membranous, net-veined wings without hairy covering, those of the two pairs being usually alike, the absence of abdominal cerci, and the presence of six or eight Malpighian tubes.

The Myrmeleonidae are large insects with short clubbed feelers on their prominent heads, and two pairs of closely similar net-veined wings, with regular oblong areolets at the tips.

They are abundantly distinct from the Neuroptera and Mecaptera, through the absence of mandibles in the imago, the maxillae - both pairs of which possess the typical inner and outer lobes and jointed palps - forming a suctorial apparatus.

It is impermeable to water, and is therefore used in northern countries for roofing, for domestic utensils, for boxes and jars to contain both solid and liquid substances, and for a kind of bark shoes, of which it is estimated 25 millions of pairs are annually worn by the Russian peasantry.

Muskdeer are hardy, solitary and retiring animals, chiefly nocturnal in habits, and almost always found alone, rarely in pairs and never in herds.

There are thus two pairs of coelomic ducts.

Among the Amphineura we find one pair of coelomic ducts in the Aplacophora, two pairs in the Chitons.

Assuming that these ancestral forms resembled the existing Nautilus in their internal anatomy, they had two pairs of renal ducts and one pair of genital ducts, which would apparently indicate, not a single metamere or unsegmented body, but three metameres.

There are however only two pairs of branchiae.

In Nautilus two pairs of auricles are present, corresponding with the two pairs of ctenidia.

The central nervous system may be described as consisting of a collar surrounding the oesophagus, and two pairs of cords arising from the collar and passing backwards.

The two pairs of cords arise from the same point of the collar.

The teats vary in number from a single abdominal pair in the guinea-pig to six thoracico-abdominal pairs in the rats; while in the Octodontidae and Capromyidae they are placed high up on the sides of the body.

In general habits and appearance these animals recall large jerboas, from which group they are, however, distinguished by the four pairs of rooted cheek-teeth, the premolars being as large as the molars, and the latter having one outer and one inner enamel-fold.

They are small rat-like rodents, with one pair of upper premolars, which are mere pins, as is the last molar, and the two pairs of limbs of normal length, with the metatarsals separate; the infra-orbital opening in the skull being triangular and widest below, while the incisive foramina in the palate are elongated.

There are three pairs of rooted molars, whose crowns carry transverse plates, decreasing in number from three in the first to one in the last tooth.

The last representatives of the Muridae are confined to Australasia and the Philippines, and constitute the sub-family Hydromyinae, characterized by the very general presence of only two pairs of molars in each jaw.

Finally, the Philippine Rhynchornys is represented by a rat with two pairs of molars and a long shrew-like nose, the zygomatic arch of the skull being also placed unusually far backward.

In both genera there is only a single pair of premolars in each jaw, but in the smaller Myoscalops there are usually three pairs of these teeth.

The most remarkable members of the family are the sand-rats of Somaliland and Shoa, forming the genera Heterocephalus and Fornarina, in which the premolars may be reduced to two pairs.

The upper lip is cleft, the jugal lacks an inferior angle, the fore part of the skull is short and broad; the cheek-teeth are partially rooted, with external and internal enamel-folds, the soles of the feet are smooth, there are six pairs of teats, the clavicles are imperfect and the tail is not prehensile.

All the New World porcupines, representing the family Erethizontidae (or Coendidae) are arboreal in their habits, and have the upper lip undivided, the cheek-teeth rooted, the clavicles complete, the soles of the feet tuberculated and three pairs of teats.

The remaining rodents, which include two families - the picas (Ochotonidae) and the hares and rabbits (Leporidae) - constitute a second sub-order, the Duplicidentata, differing from all the foregoing groups in possessing two pairs of incisors in the upper jaw (of which the second is small, and placed directly behind the large first pair), the enamel of which extends round to their postericr surfaces.

At birth there are three pairs of incisors, but the outer one is soon lost.

In the Liu-Kiu rabbit (Pentalagus furnessi) the coat is equally harsh, but the ears and hind-feet are shorter, and there are only five (in place of the usual six) pairs of upper cheek-teeth.

In general dental characters, especially the retention of three pairs of molars, this genus approximates to the Leporidae, although in the absence of post-orbital processes and the pattern of the molars it departs less widely from the modern Ochotonidae than does Prolagus.

When a large number of cocoons are to be combined into one strand they may be reeled from the tray in four sets, which are first crossed in pairs, then combined into two, and those two then crossed and afterwards combined into a single strand.

He determined that definite absorption bands are only produced by substances in which three pairs of carbon atoms are doubly linked together, as in the benzene ring.

The milk-dentition includes three pairs of incisors and one of canines in eachaw.

This animal, whose remains occur in the Lower Pliocene of both Attica and Samos, was about the size of a donkey, and possessed three pairs of upper incisor teeth, of which the innermost were large and trihedral, recalling those of the existing genus.

On the other hand, the two outer pairs of incisors were in contact with one another and with the canines, so as to form on each side a series continuous with the cheek-teeth.

These are regarded as representing a distinct family, the Saghatheriidae, characterized by the possession of the full series of twenty-two teeth in the upper jaw, among which the first pair of incisors was modified to form trihedral rootless tusks, while the two remaining pairs were separated from one another and from the teeth in front by gaps.

The Galileo-Newton theory of motion is that, relative to a suitably chosen base, and with suitable assignments of mass, all accelerations of particles are made up of mutual (so-called) actions between pairs of particles, whereby the two particles forming a pair have accelerations in opposite directions in the line joining them, of magnitudes inversely proportional to their masses.

Some pairs of liquids are soluble in each other in all proportions, but, in general, when dealing with solutions of solids or gases in liquids, a definite limit is reached to the amount which will go into solution when the liquid is in contact with excess of the solid or gas.

Why are some pairs of liquids miscible in each other in all proportions, while other pairs do not mix at all, or only to a limited extent?

Other pairs of alloys, showing more complicated relations, are described in Alloy.

Experiments on alloys are, in some ways, easier to make than on pairs of non-metallic substances, partly owing to the possibility of polishing sections for microscopic examination, and the investigation of alloys has done much to elucidate the general phenomena of solution, of which metallic solution constitutes a special case.

The prothorax is short and the mesothorax very long, the three pairs of legs closely similar, the wings often highly modified or absent, and the cerci short and unjointed.

Scudder have revealed insects with the general aspect of cockroaches and phasmids, but with the two pairs of wings similar to each other in texture and form.

Generally it is found singly or in pairs, or at most in small herds of from eight to ten, and is not inclined to attack other animals or human beings.

In these cases we should expect to find some reduced process of fertilization similar to that of Humaria granulata among the ordinary Ascomycetes, where in the absence of the antheridia the female nuclei fuse in pairs.

It is a native of the Island of Ceram, where it is said to live in pairs, feeding on fruits and herbs, and occasionally on small animals.

The wings are somewhat feeble, and the legs have the toes placed in pairs, two before and two behind.

Sometimes in very favourable soils and with vigorous trees two pairs of branches may be obtained in one season by summerstopping the erect shoots and selecting others from the young growths thus induced, but more commonly the trees have to be built up by forming one pair of branches annually.

The gills are thus metamerically repeated; there may be from four to eighty pairs, but there is these, and all round the animal, is the mantle-skirt.

Two pairs of glands open into the buccal cavity, and at the junction of pharynx and oesophagus is another pair called the sugar glands.

From this pass off two pairs of cords, the pleural and pedal, in Proneomenia separate from their origin, in Neomenia united at first and diverging at a pleural ganglion.

There are two closely connected cerebral ganglia, from which arise the usual two pairs of nerve cords.

In Cystopus Bliti the oosphere contains numerous nuclei, and all the male nuclei from the antheridium pass into it, the male and female nuclei then fusing in pairs.

In some forms we find definite male and female sexual organs (Sphaerotheca, Pyronema, &c.), in others the antheridium is abortive or absent, but the ascogonium (oogonium) is still present and the female nuclei fuse in pairs (Lachnea stercorea, Humaria granulata, Ascobolus furfuraceus); while in other forms ascogonium and antheridium are both absent and fusion occurs between vegetative nuclei (Humaria rutilans, and probably the majority of other forms).

There is apparently a reduced sexual process by the fusion of the ascogonial (female) nuclei in pairs.

Functional male and female organs have been shown to exist in Pyronema and Boudiera; in Lachnea stercorea both ascogonia and antheridia a are present, but the antheridium a1 is non-functional, the ascogonial _s- - (fema l e) nuclei fusing in pairs; /'y' this is also the case' in Humaria /;' h; granulate and Ascobolus furfurs -./ '"aceus, where the antheridium is _ / /, - entirely absent.

Indeed, the whole German production of acid Bessemer steel in 1899 was at a rate but slightly greater than that here given for one pair of American converters; and three pairs, if this rate were continued, would make almost exactly as much steel as all the sixty-five active British Bessemer converters, acid and basic together, made in 1899.

There is a regulating arrangement, by which onehalf of the guide-passages can be shut off in pairs from the water, and at the same time air is freely admitted into these unused passages by pipes which pass through the hinges of the controlling shutter.

There are nine pairs of shortly-stalked leaflets (foliola, pinnae), and an odd one at the extremity.

The pairs alternate leaves, and the nodes are separated so are placed at right ranged in a penthat each leaf is placed at angles alternately, tastichous or different height on the stem, or in what is called quincuncial manthe leaves are alternate

The temperatures indicated by the different pairs of wires differed by as much as 10 %, but the mean of the whole would probably give a fair average.

In this way he established the famous theorem that the intersections of the three pairs of opposite sides of a hexagon inscribed in a conic are collinear.

All the Crocodilia possess two pairs of musk-glands in the skin; one is situated on the inner side of the lower jaw.

Pairs of deities whose personalities are often blended or interchanged are Hathor and Nut, Sakhmi and Pakhe, Seth and Apophis.

Brontops seem scarcely separated from the type genus; but the name Brontotherium is applied to species with two pairs of incisor teeth in both jaws.

On the other hand, Palaeosyops is connected with Titanotherium by means of Telmatotherium of the upper Bridger and Washakia Eocene, a larger animal, with a longer and flatter skull, showing rudiments of horn-cores, only two pairs of lower incisors, and a general approximation in dental character to Titanotherium.

Paolo fuori le Mura at Rome, with pairs of small columns supporting arches, and decorations in coloured mosaic ("Cosmatesque" work).

In Coleochaetaceae the branches are often welded into nexion with each whorl there arise, singly or in pairs, branches which a plate, simulating a parenchyma.

In Fucus vesiculosus they arise in lateral pairs; in Ascophyllum they are single and median; in Macrocystis one vesicle arises at the base of each thallus segment; in Sargassum and Halidrys the vesicles arise on special branches.

These are the two pairs of saints, St John with St Peter in front and St Paul with St Mark in the background.

In common with lemmings and other representatives of the Microtinae, voles are, however, broadly distinguished from typical rats and mice by the structure of their three pairs of molar teeth.

Pecora, or true ruminants as they may be conveniently called, have complex stomachs and chew the cud; they have no upper incisor teeth; and the lower canines are approximated to the outer incisors in such a manner that the three incisors and the one canine of the two sides collectively form a continuous semicircle of four pairs of nearly similar teeth.

The Langaza tomb had unusually elaborate architectural ornaments and two pairs of doors, one of wood, the other of marble.

If, however, a series of leaves from the same tree be examined in pairs, the fact that one leaf from the tree is known to possess an abnormal number of veins makes it probable that the next leaf chosen from the same tree will also be abnormal-or, in other words, the fact that leaves are borne by the same tree establishes a correlation between them.

The pairs so formed were collected in a table, from which the correlation between the first leaf and the second leaf of a pair, chosen from one tree, could be determined by the methods indicated in the article Probability.

Such units frequently occur in pairs, one member of the pair being characterized by the presence, the other by the absence of a problematical body at least comparable with a ferment, the result of the presence or absence being a notable modification of the whole organism or of parts of it.

The larvae are aquatic, active, armed with strong sharp mandibles, and breathe by means of seven pairs of abdominal branchial filaments.

And in the Anguttara we find set out in order first of all the units, then all the pairs, then all the trios, and so on.

These summits are remarkable, not only for their great height, but also for their apparent symmetrical arrangement in parallel lines, sometimes in pairs facing each other across this cyclopean passage.

In Protolabis of the Middle Miocene, while no cannon-bone is formed, the first and second pairs of incisor teeth are retained, and the limbs and feet are short and disproportionately small.

Here the metacarpals and metatarsals have partially united to form cannonbones, the skull has assumed the elongated form characteristic of modern camels, with the loss of the first and second pairs of upper incisors, and the development of gaps in front of and behind each of the next three teeth, that is to say, the third incisor, the canine and the first cheek-tooth.

The species of Camelops were probably fully as large as llamas, and some, at any rate, resembled these animals as regards the number of teeth, the incisors being reduced to one upper and three lower pairs, and the cheekteeth to four or five in the upper and four in the lower jaw; the total number of teeth thus being 28 or 30 in place of the 44 of Poebrotherium.

Under the title of essence are discussed those pairs of correlative terms which are habitually employed in the explanation of the world - such as law and phenomenon, cause and effect, reason and consequence, substance and attribute.

It has the same moderately long, plump body, with a low dorsal crest, the continuation of the membrane bordering the strongly compressed tail; a large thick head with small eyes without lids and with a large pendent upper lip; two pairs of well-developed limbs, with free digits; and above all, as the most characteristic feature, three large appendages on each side of the back of the head, fringed with filaments which, in their fullest development, remind one of black ostrich feathers.

Associated with Marduk was his consort Sarpanit, and grouped around the pair as princes around a throne were the chief deities of the older centres, like Ea and Damkina of Eridu, Nebo and Tashmit of Borsippa, Nergal and Allatu of Kutha, Shamash and A of Sippar, Sin and Ningal of Ur, as well as pairs like Ramman (or Adad) and Shala whose central seat is unknown to us.

While Anu, with whom there was associated as a pale reflection a consort Antum, assigned to him under the influence of the widely prevalent view among the early Semites which conceived of gods always in pairs, remained more or less of an abstraction during the various periods of the Babylonian-Assyrian religion and taking little part in the active cult of the temples, his unique position as the chief god of the highest heavens was always recognized in the theological system developed by the priests, which found an expression in making him the first figure of a triad, consisting of Anu, Bel and Ea, among whom the priests divided the three divisions of the universe, the heavens, the earth with the atmosphere above it, and the watery expanse respectively.

These Losses Were As Far As Possible Eliminated By Combining The Trials In Pairs, With Differ Ent Loads On The Brake, Assuming That The Heat Loss Would Be The Same In The Heavy And Light Trials, Provided That The External Temperature And The Gradient In The Shaft, As Estimated From The Temperature Of The Bearings, Were The Same.

These Variations, So Far As They Were Of A Purely Accidental Nature, Would Be Approximately Eliminated On The Mean Of A Large Number Of Trials, So That The Accuracy Of The Final Result Would Be Of A Higher Order Than Might Be Inferred From A Comparison Of Separate Pairs Of Trials.

In 1784 Christian Mayer published a catalogue of all the double stars then known, which contained 89 pairs.

Undoubtedly a large number of these are only optical pairs, but mere considerations of probability show that the majority must be physically connected.

Equulei, 13 Ceti and Pegasi are all extremely close pairs, and can only be resolved with the most powerful instruments.

As a rule contrasted colours are shown by pairs having a bright and a faint component which are relatively wide apart; brilliant white stars frequently have a blue attendant - this is instanced in the case of Regulus and Rigel.

The most important apparent exceptions to Raoult's law in dilute solutions are the cases, (I) in which the molecules of the dissolved substance in solution are associated to form compound molecules, or dissociated to form other combinations with the solvent, in such a way that the actual number of molecules n in the solution differs from that calculated from the molecular weight corresponding to the accepted formula of the dissolved substance; (2) the case in which the molecules of the vapour of the solvent are associated in pairs or otherwise so that the molecular weight m of the vapour is not that corresponding to its accepted formula.

Statics of a System of ParticlesWe assume that the mutual forces between the pairs of particles, whatever their nature, are subject to the Law of Action and Reaction (Newtons Third Law); i.e.

The problem of determining the possible configurations of equilibrium of a system of particles subject to extraneous forces which are known functions of the positions of the particles, and to internal forces which are known functions of the distances of the pairs of particles between which they act, is in general determinate For if n be the number of particles, the 3n conditions of equilibrium (three for each particle) are equal in number to the 351 Cartesian (or other) co-ordinates of the particles, which are to be found.

As regards the funicular diagram, let LM be the line on which the pairs of corresponding sides of the two polygons meet, and through it draw any two planes w, w.

A, B, C are the moments of inertia about the co-ordinate axes, and F, G, H are the products of inertia with respect to the pairs of co-ordinate planes.

These may be divided into two categories; we have first, the extraneous forces exerted on the various particles from without, and, secondly, the mutual or internal forces between the various pairs of particles.

There may be several or an indefinite number of lines of connection, or there may be but one; and a line of connection may connect either the same pair of points or a succession of different pairs.

It is required to find, first, how many pairs of teeth must pass the line of contact of the pitch-surfaces before I and T work together again (let this number be called a); and, secondly, with how many different teeth of the larger wheel the tooth t will work at different times (let this number be called b); thirdly, with how many different teeth of the smaller wheel the tooth T will work at different times (let this be called c)

The length of the path of contact should be such that there shall always be at least one pair of teeth in contact; and it is better still to make it so long that there shall always be at least two pairs of teeth in contact.

In order that there may always be at least two pairs of teeth in action, each of those arcs should be equal to the pitch.

Wrapping ConnectorsBelts, Cords and Chains Flat belts of leather or of gutta percha, round cords of catgut, hemp or other material, and metal chains are used as wrapping connectors to transmit rotatory motion between pairs of pulleys and drums.

Coupling of Parallel Axes.Two or more parallel shafts (such as those of a locomotive engine, with two or more pairs of driving wheels) are made to rotate with constantly equal angular velocities by having equal cranks, which are maintained parallel by a coupling-rod of such a length that the line of c000exion is equal to the distance between the axes.

These combinations of pieces are known individually as kinematsc pairs of elements, or briefly kinematic pairs.

The three pairs mentioned above have each the peculiarity that contact between the two pieces forming the pair is distributed over a surface.

Kinematic pairs in which contact takes place along a line only are classified as higher pairs.

A kinematic link of the simplest form is made by joining up the halves of two kinematic pairs by means of a rigid link.

Compound chains are formed by the super-position of two or more simple chains, and in these more complex chains links will be found carrying three, or even more, halves of kinematic pairs.

A chain built up of three turning pairs and one sliding pair, and known as the slider crank chain, is shown in fig.

Friction of Teeth.Let N be the normal pressure exerted between a pair of teeth of a pair of wheels; s the total distance through which they slide upon each other; n the number Of pairs of teeth which pass the plane of axis in a unit of time; then nf NI (63)

Revolving pendulums are usually constructed with pairs of rods y b and bobs, as OB, Ob, hung at opposite sides of the spindle, that the centrifugal forces exerted at the point 0 may balance A each other.

The main musculature can be seen through the thin skin to be divided into about sixty pairs of muscle-segments (myotomes) by means of comma-shaped dissepiments, the myocommas, which stretch between the skin and the central skeletal axis of the body.

The first part of the alimentary canal consists of the pharynx or branchial sac, the side walls of which are perforated by upwards of sixty pairs of elongated slits, the gill-clefts.

There are two pairs of specialized cerebral nerves innervating the praeoral lobe, and provided with peripheral ganglia placed near the termination of the smaller branches.

Corresponding with each pair of myotomes, and subject to the same alternation, two pairs of spinal nerves arise from the neurochord, namely, a right and left pair of compact dorsal sensory roots without ganglionic enlargement, and a right and left pair of ventral motor roots composed of loose fibres issuing separately from the neurochord and passing directly to their termination on the muscle-plates of the myotomes.

Of the corresponding pairs of appendages thirteen belong to the head and trunk, two pairs of antennae, one pair of mandibles, two pairs of maxillae, followed by three which may be all maxillipeds or may help to swell the number of trunk-legs to which the next five pairs belong.

The abdomen or pleon carries the remaining six pairs, of which from three to five are called pleopods and the remainder uropods.

The slender pleon has always six distinct segments, the sixth carrying two-branched uropods, the preceding five armed with no pleopods in the female, whereas in the male the number of pairs varies from five to none.

Like the genuine isopods, they have seven pairs of trunk-legs, but instead of having seven segments of the middle body (or peraeon) FIG.

From the above-named isopods the present order is strongly differentiated by having heart and breathing organs not in the pleon, but in the peraeon, or middle body, the more or less simple branchial vesicles being attached to some or all of the last six pairs of trunklegs.

Normally the pleon carries six pairs of two-branched appendages, of which the first three are much articulated flexible swimming feet, the last three few-jointed comparatively indurated uropods.

The air-tube system is developed in varying degree in different bristle-tails, the number of pairs of spiracles being three (Campodea), nine (Machilis), ten (Lepisma), or eleven (Japyx).

If, however, pairs of metallic disks, made, say, of zinc and copper, are alternated with disks of cloth wetted with a conductor of the second class, such, for instance, as dilute acid or any electrolyte, then the effect of the feeble potential difference between one pair of copper and zinc disks is added to that of the potential difference between the next pair, and thus by a sufficiently long series of pairs any required difference of potential can be accumulated.

In July 1808 Davy laid a request before the managers of the Royal Institution that they would set on foot a subscription for the purchase of a specially large voltaic battery; as a result he was provided with one of 2000 pairs of plates, and the first experiment performed with it was the production of the electric arc light between carbon poles.

The breaking is done by passing the stalks between grooved or fluted rollers of different pitches; these rollers, of which there may be from 5 to 7 pairs, are sometimes arranged to work alternately forwards and backwards in order to thoroughly break the woody material or " boon " of the straw, while the broken " shoves " are beaten out by suspending the fibre in a machine fitted with a series of revolving blades, which, striking violently against the flax, shake out the bruised and broken woody cores.

The skull, which must have consisted of hardened cartilage, exhibits pairs of nasal and auditory capsules, with a gill-apparatus below its hinder part, but no indications of ordinary jaws.

The standard number of pairs is sixty-three, but different lengths obtain.

The strippers and workers are in pairs, of which there may be two or more.

The main difference between a breaker card and a finisher card is that the latter is fitted with finer pins, that it contains two doffing rollers, and that it usually possesses a greater number of pairs of workers and strippers - a full circular finisher card having four sets.

All colours are complementary, or go in pairs; each pair makes up the whole activity of the retina, and so is equivalent to white; and the two partial activities are so connected that when the first is exhausted the other spontaneously succeeds.

Such pairs of colour may be regarded as infinite in number; but there are three pairs which stand out prominently, and admit of easy expression for the ratio in which each contributes to the total action.

When the instrument is to be used to determine the potential difference between two conductors, they are connected to the two opposite pairs of quadrants.

Blondlot and P. Curie afterwards suggested that a single electrometer could be constructed with two pairs of quadrants and a duplicate needle on one stem, so as to make two readings simultaneously and produce a deflection proportional at once to the power being taken up in the inductive circuit.

The light-coloured, glossy, horizontal cones are generally in pairs, but sometimes three or four together.

P. mitis, the yellow pine of the northern and middle states of America, is rather allied to the three-leaved section, but the leaves are mostly in pairs.

Of these the principal are the Egerton, Morpeth, Morpeth Branch and Wallasey Docks; while the Alfred Dock, with its three entrances, nineteen pairs of lock-gates, 8 acres.

Three couches were prepared for three pairs of gods - Apollo and Latona, Hercules and Diana, Mercury and Neptune.

Similar honours were paid to other divinities in subsequent times - Fortuna, Saturnus, Juno Regina of the Aventine, the three Capitoline deities (Jupiter, Juno, Minerva), and in 217, after the defeat of lake Trasimenus, a lectisternium was held for three days to six pairs of gods, corresponding to the twelve great gods of Olympus - Jupiter, Juno, Neptune, Minerva, Mars, Venus, Apollo, Diana, Vulcan, Vesta, Mercury, Ceres.

Middendorff estimated the number of tusks which have yearly come into the market during the last two centuries at at least a hundred pairs, but Nordenskiiild considers this estimate too low.

The Parlement was at the same time the court of peers (tour des pairs).

Instead of calculating the direction and magnitude of the resultant force on each particle arising from the action of neighbouring particles, he formed a single expression which is the aggregate of all the potentials arising from the mutual action between pairs of particles.

Coypu are abundant in the fresh waters of South America, even small ponds being often tenanted by one or more pairs.

It will be sufficient here to define them as Arthropoda for the most part of aquatic habits, having typically two pairs of antenniform appendages in front of the mouth and at least three pairs of post-oral limbs acting as jaws.

The three pairs of appendages present in the " nauplius " larva show certain peculiarities of structure and development which seem to place them in a different category from the other limbs, and there is some ground for regarding the three corresponding somites as constituting a " primary cephalon."

In the Phyllopoda they are for the most part all alike, though one or two of the anterior pairs may be specialized as sensory (Apus) or grasping (Estheriidae) organs.

In the Cirripedia (Thyrostraca) the six pairs of biramous cirriform limbs differ only slightly from each other, and in many Copepoda this is also the case.

In the thoracic series it is usual for one or more of the anterior pairs to be pressed into the service of the mouth, forming " foot-jaws " or maxillipeds.

In the Decapoda three pairs are thus modified, and in the Tanaidacea, Isopoda and Amphipoda only one.

In the other Malacostraca the heart is generally abbreviated, and even where, as in the Amphipoda, it is elongated and tubular, the ostia are restricted in number, three pairs only being usually present.

The most important excretory or renal organs of the Crustacea are two pairs of glands lying at the base of the antennae and of the second maxillae respectively.

In addition to these two pairs of glands, which are in all probability the survivors of a series of segmentally arranged coelomoducts present in the primitive Arthropoda, other excretory organs have been described in various Crustacea.

In the primitive Phyllopoda the ventral chain retains the ladder-like arrangement found in some Annelids and lower worms, the two halves being widely separated and the pairs of ganglia connected together across the middle line by double transverse commissures.

In the Phyllopoda it consists mainly of two pairs of ganglionic centres, giving origin respectively to the optic and antennular nerves.